Gas-cooled torch lamp

ABSTRACT

An infrared heating device includes a pistol grip handle carrying a lamp and a reflector spaced therefrom for focusing infrared radiation upon work to be heated. A filter is positioned over the front of the reflector for passing only infrared radiation to the work. Means are provided to establish a flow of cooling gas over the exterior and interior of the reflector and over in inner and outer faces of the filter. A flow-responsive switch is provided in the handle for detecting the flow of cooling gas. A solid state switching device (Triac) is connected in circuit with the lamp and actuated by the flow-responsive for energizing the lamp only when a flow of cooling gas is established.

United States Patent 11 Ray Feb. 12, 1974 GAS-COOLED TORCH LAMP 3,375,366 3/1968 Scheppe 240/47 1,006,767 10/1911 Mauger 219/377 UK [751 lnvenior- J'mmy Demon 2,131,484 9/1938 Ringwald... 219/343 x [73] Assignee: Industrial Innovations Inc., Denison, 23173426 4/1943 Wilson 219/354 X Tex 3,235,708 2/1966 Kirk 219/343 X [22] Filed: Man 30, 1972 FOREIGN PATENTS OR APPLICATIONS 745,700 2/1956 Great Britain 219/353 [21] Appl. No.: 239,692

Primary Examiner-1 Bartis 52 US. Cl 219/343, ZOO/81.9 M, 240/47, Attorney, Agent, or Firm-Wendell Coffee 250/88, 219/347, 219/358, 219/377, 219/354 [51] Int. Cl. HOSb 1/02, H0513 3/00, F2lv 29/00 1 1 ABSTRACT 1 Field of Search-m 346-353, An infrared heating device includes a pistol grip han- 128/395, dle carrying a lamp and a reflector spaced therefrom 396; 250/881 89,86; M for focusing infrared radiation upon work to be heated. A filter is positioned over the front of the re- 1 References Cited flector for passing only infrared radiation to the work. UNITED STATES PATENTS Means are provided to establish a flow of cooling gas 2,295,863 9/1942 Paradis 219/343 UX over the exterior and interior of the reflector and Over 2,449,362 9/1948 Bell et a1 240/47 X in inner and Outer faces o h fil er. A flow- 3,492,459 1/1970 Schwartz 219/251 responsive switch is provided in the handle for detect- 3,242,314 3/1966 Eckles 219/343 X ing the flow of cooling gas. A solid state switching de- .331. /1967 Ed rds et 1 3 X vice (Triac) is connected in circuit with the lamp and L 8 8 8 v l actuated by the flow-responsive for energizing the oore 3,239,651 3/1966 Silbermanm. 219/343 x lamp only when a flow of coolmg gas estabhshed' 2,105,430 1/1938 3 Claims, 3 Drawing Figures Metcalf 219/343 UX I lIllI IIIIA i k1 I.

POrA/E Z ELECTEI PATENTEDFEB 1 2 3' 792 230 SHEET 2 UF 2 l4 POWER SOURCE or M, X272 ELECTRICITY 1 GAS-COOLED TORCH LAMP CROSS-REFERENCE To RELATED APPLICATIONS This application shows mechanism for operating a gas-cooled torch lamp. I filed a design application showing a manually operated switch and no cooling gas on Jan. 27, 1971, Ser. No. D-l 10,381 which issued as Pat. No. Ii- 223,960 on Jan. 16, 1973. No claim for priority 1s made.

BACKGROUND OF THE INVENTION Field of the Invention This invention relates to radiant-type electrical heating with an infrared heating element having a reflector therefor.

Description of the Prior Art Prior to my invention'in this field, known devices of which I am aware include an iodine quartz lamp which produces brilliant light and infrared heat waves. These lamps are well known and are commercially available on the market. Also, it is known that filters may be used with these lamps which are basically partially silvered mirrors. These filters will pass the heat waves and reflect the visible light rays. If the lamp is being used for a light source, the light can be reflected to its desired location and the illuminated object is not also heated. It was known to use the filters with reflectors and to shieldthe work from the visible light when using the lamp as a heat source. Otherwise the lamp illuminates the object so brillinatly the workman is blinded by the light upon the object and cannot as readily see the progress of his work. Before my invention in the field, the common electrical elements which I use, such as the magnetic responsive switch and the Traic" power relay, were well known and commercially available on the market.

.However, with the prior art devices, the intense heat produced by the lamp tends to destroy normal reflectors. The heat produced by the lamp tends to heat the surface of the reflectors to an extremely high temperature so the reflectors are destroyed. A great deal of work has been done to provide reflectors which are not destroyed by the heat. For example see U.S. Pat. No. 3,284,225.

SUMMARY OF THE INVENTION New and Different Function I have discovered that the most efficient way to make heat lamps for soldering and the like with an intensely focused heat ray is to cool the reflector rather than attempt to make the reflector heat resistant. I accomplished this by flowing cooling gas around the reflector. The cooling'gas may be either air or an inert gas such as nitrogen.

It is important that the lamp not be energized unless there is a flow of cooling gas. If the lamp operates without the flow of cooling gas, the heat from the lamp will destroy the reflector. These devices are often used by telephone installation men in underground tuunels or manholes where there is sometimes an explosive atmosphere of methane, acetylene, propane or the like. Where this situation exists, it is essential that the temsphere.

I have solved the probelm by switching on the lamp responsive to cooling gas flow. Although this switching on could be done by a simple flap valve in the conduits having the glas flow and have the movement of the flap valve actuate a microswitch, this is not the system I have illustrated. The preferred system which is illustrated is to place a magnet in the cooling gas conduit. Therefore, a flow of cooling gas in the conduit will move the magnet. The movement of the magnet is detected by a magnetic switch. However they usually do I not have a sufficient current carrying capability; therefore, it is necessary to use a relay or a triac to switch on the lamp responsive to the closing of the magnetic switch. This has the additional advantage of the magnetic switch and the triac being within hermetically sealed containers so there is no danger of the production of a spark from them.

OBJECTS OF THIS INVENTION An object of this invention is to provide a lamp to concentrate heat upon a small area of an object.

Another object is to make such a lamp usable in an explosive atmosphere.

Further objects are to achieve the above with a device that is sturdy, compact, durable, lightweight, simple, safe, efficient, versatile, and reliable, yet inexpensive and easy to manufacture, operate, and maintain.

Still further objects are to achieve the above with a method that is versatile, rapid, efficient, and inexpensive, and does not require skilled people to adjust, operate, and maintain.

The specific nature of the invention, as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawing, the different views of which are not necessarily to the same scale.

I BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a longitudinal sectional view of an apparatus according to this invention with some parts shown schematically for clarity and with arrows showing the flow of cooling gas through the apparatus.

FIG. 2 is a schematic representation of the electrical circuits as used therein.

FIG. 3 is a sectional view particularly showing some of the air passage with the shroud removed, taken sub stantially on line 33 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring specifically to FIG. 1 of the drawing, it may be seen that the apparatus has handle or base 10. The handle 10 is conveniently in the form of a pistol grip so the workman can readily hold itin his hand and direct the heat rays from the device upon the work area. The overall appearance of the device is more readily seen from the drawings in my design patent application referred to above.

Gas connection 12 is at the bottom of the handle 10. Not shown in FIG. 1 is electrical connections 41 at the bottom of the handle 10. FIG. 2 shows the electrical connection 14 in the form of a conventional electrical power cable which connects the device to a power source of electricity 16. The gas connection 12 is connected by conventional gas hose to a source of cooling gas under pressure 18. The gas source 18 might well be compressed air from a conventional storage tank or from a gas compressor it might be from a bottle of inert gas such as nitrogen.

Heating insulating discs 20 and plenum chamber 22 are attached to the handle on the opposite end of the pistol grip from the gas connector 12. Lamp holder disc 24 is attached to the plenum chamber 22. The disc 24 has a plurality of small gas discharge holes 26 therein which are arranged along the perimeter thereof. Lamp holder socket 28 is centrally attached to the disc 24. The lafnp holder socket 28 is not shown in detail inasmuch as it is of conventional commercial design as is iodine quartz lamp 30 therein. The lamp 30 produces infrared radiation asbrilliant, visible light.

Shroud 32' is circular in cross section and is telescoped over and securely attached to the outside of the plenum chamber 22. It is made by conventional tachniques of thin walled aluminum material. As readily seen in FIG 1, filter end 34 of the shroud 32 is much larger in diameter than the end which connects onto the plenum chamber 22.

' Attachment ring 36 is telescoped within the shroud 32 at the filter end 34. The filter 40 rests upon internal shoulder 38 of the ring 36. These are a plurality of air passageways or filter openings 42 in the form of notches cut along the surface of the ring 36.

The filter 40 is held in place by spring clips 44 which themselves are held in place by screws 46. The screws 46 form an anchor by which one end of tension springs 48 are attached. The tension springs 48 extend from the screws 46 to a hook at opening 50 of reflector 52. The reflector 52 is a conventional parabolic shaped reflector made of polished aluminum. Because of the cooling which I describe, it is not necessary to use a heat resistant metal nor is itnecessary to take elaborate precautions to prevent the reflecting surface of the reflector from becoming dulled. As may be seen from the above description and the drawings, the reflector is held in place by the springs 48 holding them firmly against the spring clips 44. I

Air passage 54 is between the reflector '52 and the shroud 32. If air is supplied to the interior of the plenum chamber 22, it will pass through the holes 26 in the mounting disc 24 to within the shroud 32 and along the outside of the reflector 52 and through the openings 42 to blow along the outside surface of the filter 40. There is another flow of gas which would be through the opening 50, around the lamp 30, and between the reflector 52 and the filter 40, and then through the air passageways 42.

The base 10 has conduit 56 for gas passage leading from the gas connection 12 to valve chamber 58. The valve chamber 58 is axially aligned with conduit 60 which extends from the valve chamber 58 to the plenum chamber 22, through discs 20.

Valve 62 is mounted within the valve chamber 58 and is operated by hand knob 64 on the exterior of the handle 10. When the valve knob 64 is pulled outward,

connection 12. Spacer is within the conduit so when the valve 62 is open and the gas pushesthe magnet 66 upward, the magnet is properly positioned. The spacer 70 has a hole therein so it does not impede the flow of gas around and therethrough.

Gas flow repositions the magnet 66 relative to magnetic switch 72 so that it closes the magnetic switch. The arrangement of magnetic switches with magnets is well known to the art, however, the movement of the magnets by gas flow and also using it in this particular arrangement is considered to beinvention by me.

Referring specifically to FIG. 2, the schematic representation of the electrical circuits shows the power source of electricity 16 connected to the lamp 30. One wire is directly connected, the other wire is connected to the source through triact 74 when the triac is closed. The triac will be recognized as a switching means or means for connecting power from the power source to the lamp 30. The switch 72 is electrically connected between the power source 16 and the control connection of the triac 74 through resister 76. The switch 72 activates the triac so the triac closes to energize the lamp 30. All this will be understood by those skilled in the art.

It will be understood that this disclosure does not go into detail upon either existing elements which are well known to the art and commercially available, nor does it go into detail on techniques which are well known to the art and therefore, are within the skill of ordinary craftsmen. E.g., FIG. 1 does not show the physical placement of the triac 74 within the handle 10 because applicant believes that any mechanic ordinarily skilled in tools of this sort would readily be able to place the triac within a cavity within the handle 10'and connect the wires from the magnetic switch 72 to the triac and to the lamp 30.

Also, triacs are well known and able on the market.

It will be understood that the gas also cools the filter 40. The filter 40 will become the hottest part of the device. Therefore, it is important that it be cooled also. Furthermore, if the filter temperature does increase so it is above the ignition point of the atmosphere, it will still be safe because the filter will be bathed or have a gas shield around it. This will be well understood if nitrogen is used as the cooling gas. Even if compressed air is used as a cooling gas, by having the filter and the parts shielded by the compressed air, this prevents methane or other explosive mixture to be within this area.

The wiring through the handle 10 will permit some cooling gases to escape in this area. Although the triac 74 and the magnetic switch 72 are hermetically sealed, they are also bathed or shielded by the same cooling gas which flows over the lamp 30 and reflector 52.

The cooling gas itself will reach a rather high temperature. The air ports or openings or passageways 42 are cut along the surface of the ring 36 so that the air flows evenly from the edges of the filter 40 to the center of the filter; from there the air flows out along the axis of the device which is also the main heat beam coming from the lamp 30. The preheated gas which has been cooling the device blows upon the work. This will help in heating the work.

It is desirable to make the air valve 62 slow acting. This may be done two ways. One is to put threads upon the shank attached to the hand knob 64. If the valve 62 commercially availis slow acting, there will be a small gas flow, shielding the parts before there is sufficient gas flow to move the magnet 66. When the device is turned off, the gas flow is reduced sufficiently so the electricity is turned off and thereafter there is a continuing gas flow before the valve is completely closed. Another way of achieving the slow movement of the valve 62 is to make the parts extremely tight or small clearance so it is hard to move and the hand knob moves only slowly in opening and closing.

The embodiment shown and described above is only exemplary. I do not claim to have invented all the parts, elements or steps described. Various modifications can be made in the construction, material, arrangement, and operation, and still be within the scope of my invention. The limits of the invention and the bounds of the patent protection are measured by and defined in the following claims. The restrictive description and drawing of the specific example above do not point out what an infringement of this patent would be, but are to enable the reader to make and use the invention.

I claim as my invention: a

1. In an infrared heating device having a. a base,

b. a lamp attached to the base emitting infrared rays,

c. a reflector surrounding the lamp for focusing the cooling gas flow,

jj. filter openings from the passage at the filter,

kk. said filter openings forming means operatively associated with the shroud for directing the gas over the outside of the filter to also cool the filter,

mm. an opening between the lamp and reflector for flow of cooling gas between the lamp and reflector,

nn. said flow of cooling gas between the lamp and reflector also flowing on the inside of the filter and said filter openings,

k. a source of cooling gas under pressure,

m. a valve attached to the base,

n. gas conduits connecting the gas source to the valve and the valve to the passage, and

o. detecting means attached to the base and associated with one of said gas conduits for detecting a flow of gas from the gas source to the passage, and

p. means responsive to said detecting means for actuating said switch means to energize said lamp when the cooling gas is flowing to the passage from the source and to de-energize said lamp when the flow of cooling gas ceases.

2. The invention as defined in claim 1 wherein said detecting means includes:

q. a magnet within one of said conduits, and

r. said magnet is mounted for movement responsive to gas flow in the conduit said switch is magnetically responsive.

3. The invention as defined in claim 1 with the additional limitation of q. means operatively associated with the shroud for directing the gas from said passage out along the axis of the device, which is along the beam of heat as focused by said reflector. 

1. In an infrared heating device having a. A base, b. a lamp attached to the base emitting infrared rays, c. a reflector surrounding the lamp for focusing the infrared rays upon work to be heated, d. a filter attached to the reflector for blocking the light rays and passing the infrared rays, and e. a power source of electricity for the lamp; f. THE IMPROVED STRUCTURE FOR COOLING THE APPPARATUS COMPRISING: g. switch means attached to the base for connecting the lamp to the power source, h. a shroud surrounding the reflector, j. a passage between the shroud and reflector for cooling gas flow, jj. filter openings from the passage at the filter, kk. said filter openings forming means operatively associated with the shroud for directing the gas over the outside of the filter to also cool the filter, mm. an opening between the lamp and reflector for flow of cooling gas between the lamp and reflector, nn. said flow of cooling gas between the lamp and reflector also flowing on the inside of the filter and said filter openings, k. a source of cooling gas under pressure, m. a valve attached to the base, n. gas conduits connecting the gas source to the valve and the valve to the passage, and o. detecting means attached to the base and associated with one of said gas conduits for detecting a flow of gas from the gas source to the passage, and p. means responsive to said detecting means for actuating said switch means to energize said lamp when the cooling gas is flowing to the passage from the source and to de-energize said lamp when the flow of cooling gas ceases.
 2. The invention as defined in claim 1 wherein said detecting means includes: q. a magnet within one of said conduits, and r. said magnet is mounted for movement responsive to gas flow in the conduit said switch is magnetically responsive.
 3. The invention as defined in claim 1 with the additional limitation of q. means operatively associated with the shroud for directing the gas from said passage out along the axis of the device, which is along the beam of heat as focused by said reflector. 